Collision determination apparatus, collision determination method, collision avoidance system

ABSTRACT

A collision determination apparatus is provided. The collision determination apparatus is provided with an acquiring unit that acquires a posture and movement characteristics of an object to be determined whether a collision risk is present; and a reliability determination unit that determines a reliability of the movement characteristics using the posture and the movement characteristics acquired by the acquiring unit.

CROSS-REFERENCE OF RELATED APPLICATIONS

This application is the U.S. bypass application of InternationalApplication No. PCT/JP2021/026969 filed on Jul. 19, 2021, whichdesignated the U.S. and claims priority to Japanese Patent ApplicationNo. 2020-135606 filed on Aug. 11, 2020, the contents of both of whichare incorporated herein by reference.

BACKGROUND Technical Field

The present disclosure relates to a technique used in a vehicle fordetermining a collision with an object.

Description of the Related Art

A technique is proposed in which a travelling route of an object iscalculated and it is determined whether a route intersection is presentbetween a travelling route of the own vehicle and the travelling routeof the object and whether a collision risk between the own vehicle andthe object is present.

SUMMARY

The present disclosure may be accomplished with the following aspects.

As a first aspect, a collision determination apparatus is provided. Thecollision determination apparatus according to the first aspect isprovided with an acquiring unit that acquires movement characteristicsof an object to be determined whether a collision risk is present; and areliability determination unit that calculates a movement locus of theobject using the acquired movement characteristics and determines areliability of the calculated movement locus of the object.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other objects, features, and advantages of the presentdisclosure will be more clarified by the following detailed descriptionswith reference to the accompanying drawings. In the drawings,

FIG. 1 is an explanatory diagram showing an example of a vehicle onwhich a collision determination apparatus according to a firstembodiment is provided;

FIG. 2 is a block diagram showing an example of an internalconfiguration of the collision determination apparatus according to thefirst embodiment;

FIG. 3 is a flowchart showing a collision determination process executedby the collision determination apparatus according to the firstembodiment;

FIG. 4 is an explanatory diagram showing a procedure of determining areliability by using a posture and a direction of a speed of an object;

FIG. 5 is a flowchart showing a collision determination process executedby a collision determination apparatus according to a second embodiment;

FIG. 6 is an explanatory diagram showing a procedure of determining areliability by using a posture and a movement locus of the object;

FIG. 7 is a flowchart showing a collision determination process executedby a collision determination apparatus according to a third embodiment;and

FIG. 8 is an explanatory diagram showing a procedure of determining areliability by using a difference between a plurality of speeds ofobjects acquired using detection results of a plurality of differenttypes of detection units.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Patent literature JP-A-2020-008288A discloses a technique in which atravelling route of an object is calculated and it is determined whethera route intersection is present between a travelling route of the ownvehicle and the travelling route of the object and whether a collisionrisk between the own vehicle and the object is present.

However, detection units generally include individual differences andalso detection errors possibly occur due to a disturbance depending on adetection environment. Due to the individual differences betweendetection units and the detection errors, if an error on the travellingroute of the object is large, an accuracy for determining whether aroute intersection is present between the own vehicle and the object,that is, an accuracy for determining whether a collision risk betweenthe own vehicle and the object is present may be lowered.

Hence, influence of individual difference of the detection units andenvironmental influence is required to be suppressed or eliminated toimprove the accuracy of the collision determination.

Hereinafter, a collision determination apparatus and a collisiondetermination method according to the present disclosure will bedescribed with the following embodiments.

First Embodiment

As shown in FIG. 1 , a collision determination apparatus 100 accordingto a first embodiment is used being mounted on a vehicle 50. Note thatthe collision determination apparatus 100 may be used being mounted ontwo-wheel vehicle or other mobile body other than the vehicle 50. Thecollision determination apparatus 100 according to the first embodimentconstitutes a collision determination system together with a camera 20,a millimeter wave radar 21 and a LIDAR (light detection and ranging) 22.The camera 20 is configured as an imaging device provided with animaging element such as CCD or an imaging element array and serves as adetection unit that outputs an image data as a detection resultincluding an outline information and a shape information of an objectwhich are detected when receiving visible light. The camera 20 may bedisposed on front and rear windows of the vehicle 50 and a side surfaceof a body of the vehicle 50. The millimeter wave radar 21 is configuredto emit millimeter waves and receive reflection waves reflected at anobject, thereby serving as a detection unit to detect a distance, anangle and a speed of the object relative to the collision determinationapparatus 100, that is, the vehicle 50. The reflection waves reflectedat the object are detected as one or more detection point groupscorresponding to the object. The millimeter wave radar 21 may bedisposed on front and rear bumpers of the vehicle 50, front and reargrilles 16, and front and rear windows. The LIDAR 22 is configured toemit infrared laser light and receive reflection light reflected at theobject, thereby serving as a detection unit to detect a distance, anangle and a speed of the object relative to the collision determinationapparatus 100, that is, the vehicle 50. The reflection light reflectedat the object are detected as detection point groups corresponding tothe object. The LIDAR 22 may be disposed on front and rear bumpers ofthe vehicle 50, front and rear grilles 16, and front and rear windows.The camera 30, the millimeter wave radar 21 and the LIDAR 22 can becollectively referred to as a detection unit to detect environmentalinformation around the vehicle 50. Note that positions where thedetection unit is disposed are examples, and the detection units 20, 21and 22 may be disposed at various other positions in the vehicle 50.

The vehicle 40 is further provided with a yaw rate sensor 25 fordetecting a posture of the vehicle 50, more specifically, a yaw rate asan angular velocity when the vehicle 50 is turning right or left.Moreover, the vehicle 50 is provided with a driving assist controlexecution unit 30 that executes a driving assist such as a brakingassist, a steering assist and a driving assist using information aboutthe objects around the vehicle 50 transmitted from the detection units20, 21 and 22. The collision determination apparatus 100 and the drivingassist control execution unit 30, or the collision determination systemand the driving assist control execution unit 30 constitute a collisionavoidance system 10.

As shown in FIG. 20 , the collision determination apparatus 100 isprovided with a central processing unit (CPU) 101, a memory 102 as astorage unit, an input-output interface 103 as an acquiring unit and aclock generator which is not shown. The CPU 101, the memory 102, theinput-output interface 103 and the clock generator are connected to bebi-directionally communicable with each other via an internal bus 104.The memory unit 102 includes a non-volatile read only memory such as ROMstoring a collision determination program Pr1, and a memory unit such asRAM which is readable and writable by the CPU 101. The collisiondetermination program Pr1 determines whether a collision risk with anobject is present, including a process for acquiring a direction ofspeed or a movement locus of the object by using a detected posture andmovement characteristics to determine a reliability of the speed and themovement locus and a process for determining a reliability of the speedby using the speed difference acquired from a plurality of detectionunits. For the memory 102, a non-volatile and read only dedicated regionincludes a reliability storing region 102a storing a referencereliability as a predetermined reference value and a reliability lowerthan the reference reliability which can be updated depending ondetermination of the reliability. The memory may additionally store apredetermined angle difference and a predetermined speed difference usedfor determining the reliability. The CPU 101, that is, the collisiondetermination apparatus 100 loads the collision determination programPr1 stored in the memory 102 into the readable and writable memory andexecutes the loaded program, thereby serving as a reliabilitydetermination unit and a determination unit. Note that the CPU 101 maybe a single CPU or a plurality of CPUs that execute respective programs,or may be a multi-task CPU or a multithread CPU capable ofsimultaneously executing a plurality of programs. The memory 102 mayfurther store, for example, a driving assist program for executingdriving assist processes or an autonomous driving process using adetection result of objects. According to the present embodiment, acollision avoidance assist process is mainly executed among the drivingassist processes. Note that the driving assist control execution unit 30can be referred to as a collision avoidance assist execution unit.

A camera 20, the millimeter wave radar 21 and the LIDAR 21 as detectionunits for detecting objects, the yaw rate sensor 25 and the drivingassist control execution unit 30 are each connected to the input-outputinterface 103 via a control signal line. An image control signal istransmitted to the camera 20 from the input-output interface 103 tocommand the camera 20 to perform an imaging process to detect objects,and an imaging signal indicating a captured signal as a detection resultis transmitted to the input-output interface 103 from the camera 20. Adetection control signal is transmitted to the millimeter wave radar 21from the input-output interface 103 to command the millimeter wave radar21 to emit detection waves and receive the incoming waves to detectobjects, and a distance signal and an angle signal as detection resultor an incoming wave intensity signal as a raw data is transmitted to theinput-output interface 103 from the millimeter wave radar 21. Adetection control signal is transmitted to the LIDAR 22 from theinput-output interface 103 to command the LIDAR 22 to perform emissionand reception processes to detect objects, and a distance signal and anangle signal as detection result or an incoming wave intensity signal asa raw data is transmitted to the input-output interface 103 from theLIDAR 22. A command signal is transmitted to the driving assist controlexecution unit 30 from the input-output interface 103 to command thedriving assist control execution unit 30 to perform a driving assistcontrol depending on the detection result of the objects.

With reference to FIG. 3 , a collision determination process executed bythe collision determination apparatus 100 will be described. Theprocessing routine shown in FIG. 3 is repeatedly executed atpredetermined intervals, for example, every few milliseconds, after thecontrol system of the vehicle 50 is activated or a start switch isturned ON. The CPU 101 executes the collision determination program Pr1,thereby executing the process flow shown in FIG. 3 . In the followingdescription, a case will be exemplified in which the camera 20 and themillimeter wave radar 21 are used as detection units. However, detectionunits based on other detection method such as the LIDAR 22 or anultrasonic wave sensor may be appropriately combined. In the presentembodiment, a case will be exemplified in which other vehicle is used asan object Ta having a posture with respect to the vehicle 50 providedwith the collision determination apparatus 100 shown in FIGS. 4 and 5 .The object Ta may include movable objects such as a bicycle, amotorcycle, a pedestrian, and an animal.

The CPU 101 acquires detection result of the object Ta, as an object tobe determined whether a collision risk is present, detected by thecamera 20 and the millimeter wave radar 21 via the input-outputinterface 103 (step S100). The detection result includes, for the camera20, a captured image showing a shape and a location of the object Ta.The detection result includes, for the millimeter wave radar 21,detection point group corresponding to the object Ta and the distanceand angle information of the respective detection points. The object Tais recognized by performing a pattern matching to the image captured bythe camera 20, and is recognized by executing the clustering processusing the detection point group acquired by the millimeter wave radar21.

The CPU 101 acquires a posture and movement characteristics of theobject Ta using the acquired detection result (step S102). The movementcharacteristics refers to information expressing features of theoperation or the behavior of the object Ta over time. According to thepresent embodiment, the movement characteristics may refer to a velocityvector V of the object Ta, a movement speed or a movement directionindicating showing a speed and direction in which the object Ta moves.For the posture of the object Ta, as shown in FIG. 4 , a major directionTad corresponding to the longitudinal direction of the object Ta, thatis, the travelling direction, is determined by using coordinateinformation of pixels corresponding to two or more feature points in theobject Ta recognized by the pattern matching technique, for example, twoor more corner portions, preferably three or more corner portions orfour or more feature points, and the posture of the object Ta isacquired as an angle formed between the major direction Tad and adirection orthogonal to the lateral direction in the local coordinate ofthe vehicle 50 (i.e. travelling direction of the vehicle 50).Alternatively, for the posture of the object Ta, the major direction Tadcorresponding to the object Ta may be determined by using coordinateinformation of a plurality of detection points corresponding to theobject Ta recognized by the clustering process of the detection pointgroup, for example, detection points corresponding to two or more cornerportions, preferably detection points corresponding to three or morecorner portions or four or more detection points, and the posture of theobject Ta is acquired as an angle formed between the major direction Tadand the lateral direction of the vehicle 50. The major direction of theobject Ta may refer to a movement direction or an orientation of theobject Ta. In the case where the object Ta is a pedestrian, since it isnot easy to determine the longitudinal direction, the camera 20 may beused to recognize a face of the pedestrian, the direction of the facemay be determined to be the major direction. Further, a fusionprocessing may be executed using the detection results of the camera 20and the millimeter wave radar 21, and the posture of the object Ta maybe acquired using successive fusion-derived points in which the fusionprocessing is succeeded.

For the velocity vector V of the object Ta, a detection speed as a speeddetected by the millimeter wave radar 21, that is, a detection historyof the detection speed may be used, or a movement history of the objectTa, that is, a speed history where the positional history of thedetection points is differentiated by time may be used. Further, avelocity vector used when calculating the movement locus which will bedescribed later may be utilized. Moreover, both of the detection speedand the speed history may be utilized. In this case, for example, asimple average of both speed values or a weighted average where eitherone speed value is weighted may be utilized. As shown in FIG. 4 , theacquired speed vector V of the object Ta has a direction and a magnitudeof the collision determination apparatus 100, that is, in the localcoordinate of the vehicle 50.

The CPU 101 determines the posture of the object Ta, that is, determineswhether a deviation between the major direction Tad and the velocityvector V is larger than a predetermined determination value (step S104).Specifically, the CPU 101 determines whether an angle θ formed betweenthe major direction Tad as a current direction of the object Ta and thevelocity vector at the current position is larger than the determinationangle θr, that is, determines whether it is θ>θr. The predeterminedangle θr ranges, for example, from 30° to 40° or may range from 20° to30° for more strict determination, or from 40° to 50° for more relaxeddetermination.

When determined that it is θ>θr, that is, the deviation between theposture of the object Ta and the velocity vector V is larger than thepredetermined determination value (step S104: Yes), the CPU 101 reducesthe movement characteristics, that is, the reliability of the speed(step S106). The reliability refers to an accuracy, a validity or acertainty of indexes and parameters to be determined. In this case,since the posture of the object Ta, that is, the deviation between themajor direction Tad and the velocity vector is large, and errors may becontained in the acquired posture or the velocity vector V which cannotbe tolerated, a movement behavior of the object Ta is not accuratelydetected according to the detection result of the object Ta acquired bythe camera 20 and the millimeter wave radar 21. Hence, the reliabilityof the speed acquired by using the detection result is low. For thereduction of the reliability, a variable value may be used where adegree of reduction becomes larger in proportion to a deviation anglefrom the determination angle θr, or a fixed value where a predetermineddegree is reduced may be used. The CPU 101 executes the collisiondetermination process (step S110), determines whether a collision riskbetween the object Ta and the vehicle 50 is present by using thedetermined reliability, determines the level of the driving assistprocess, transmits a command signal to the driving assist controlexecution unit 30 and terminates the present processing routine. For thedetermination whether a collision risk is present, a known method, forexample, TTC (time to collision) or a relative positional relationshipin the vehicle width direction is used to determine the collision risk.Then, a threshold value used for a collision determination depending onthe determined reliability, for example, TTCr may be changed, whereby alevel of determination whether a collision risk is present may bechanged. Alternatively, the level of the driving assist process inaccordance with the determination result may be determined withoutchanging the level of determination whether a collision risk is present.Specifically, in the case where the reliability is lower than thereference reliability, the collision determination level may be loweredby using a larger TTCr, or the driving assist control execution unit 30may be commanded to execute a lower level driving assist, that is, aweak driving assist without changing the collision determination level,or both controls may be combined. For example, in the case where abraking assist including an emergency braking is required, the collisiondetermination level is lowered to delay the braking start timing or thedriving assist level is set to be lowered to delay the braking starttiming, or the braking force is weakened.

The CPU 101 sets the reliability to be the reference reliability (stepS108) when determined that the deviation between the posture of theobject Ta and the velocity vector V is less than or equal to thepredetermined determination value (step S104: No). In the case where thedeviation between the posture of the object Ta and the velocity vector Vis less than or equal to the predetermined determination value, sincethe posture of the object Ta, that is, the major direction Tad and thedirection of the velocity vector V are matched or close to each other tobe within an allowable range, according to the detection result of theobject Ta acquired by the camera 20 and the millimeter radar 21, themovement behavior of the object Ta is accurately detected. Hence, thereliability of the speed satisfies the reference reliability. The CPU101 executes a collision determination process (step S110) to determinewhether a collision risk between the object Ta and the vehicle 50 ispresent, determine the level of driving assist in accordance with thedetermined reliability, or both controls are combined to be executed.Then the CPU 101 transmit a command signal to the driving assist controlexecution unit 30 and terminates the present process. Specifically,since the reliability is set to be the reference reliability, theprocess determines whether the collision risk is present based on adetermination level as a reference level, and commands the drivingassist control execution unit 30 to execute the driving assist processhaving a predetermined reference level.

According to the above-described collision determination apparatus 100of the first embodiment, since the posture of the object Ta and themovement characteristics of the object Ta, especially the velocityvector V of the object Ta is utilized to determine the reliability ofthe movement characteristics, the individual differences of thedetection elements and the environmental influence are suppressed orexcluded, thereby improving the collision determination accuracy.Specifically, in the case where the angle θ formed between the currentmajor direction Tad and the velocity vector at the current location islarger than the predetermined angle θr, the reliability of the velocityvector V is reduced, and in the case where an angle θ formed between thecurrent major direction Tad and the velocity vector at the currentlocation is smaller than the determination angle θr, it is determinedthat the velocity vector V satisfies the reference reliability. As aresult, even in a case where the individual differences of the detectionelements and the environmental influence are present, it can bedetermined whether a collision risk is present depending on adetermination level based on a reliability index. Further, a drivingassist level can be set depending on the reliability such that anerroneous determination and execution of unnecessary driving assistprocess are reduced, thereby improving the collision determinationaccuracy. Similar to the following embodiments, a collision avoidanceassist in the driving assist process includes, in addition to thedriving assist, a steering assist for avoiding collision with the objectby the steering operation.

Second Embodiment

A collision determination apparatus according to the second embodimentdiffers from the first embodiment where the velocity vector V of theobject V is used in that a movement locus is used as movementcharacteristics of the object Ta when determining the reliability. Sinceother configurations of the second embodiment are the same as those inthe collision determination apparatus 100 of the first embodiment, thesame reference numbers are applied to the same configurations anddetailed explanation will be omitted.

The collision determination apparatus according to the second embodimentincludes a collision determination program Pr1 stored in the memory 102.The collision determination program Pr1 functions to calculate themovement locus and determine the reliability using the posture and thecalculated movement locus. With reference to FIG. 5 , an objectdetecting process executed by a collision determination apparatus 100according to the second embodiment will be described. A processingroutine shown in FIG. 5 is repeatedly executed at predeterminedintervals, for example, every few milliseconds, after the control systemof the vehicle 50 is activated or a start switch is turned ON. The CPU101 executes the collision determination program Pr1, thereby executingthe process flow shown in FIG. 5 . In the following description, processsteps similar to those executed by the collision determination apparatus100 according to the first embodiment are applied with the samereference numbers as those in the first embodiment and the detailedexplanation will be omitted.

The CPU 101 acquires detection result of the object Ta, as an object tobe determined whether a collision risk is present, detected by thecamera 20 and the millimeter wave radar 21 via the input-outputinterface 103 (step S100). The CPU 101 acquires the posture and themovement characteristics of the object Ta (step 5102) by using theacquired detection result. The movement characteristics are theinformation indicating features of the operation and the behavior of theobject Ta over time. According to the present embodiment, the movementlocus of the object Ta is acquired as the movement characteristics ofthe object Ta. The movement locus is calculated by using the speed andthe posture of the object. For example, the velocity vector is acquiredwith an extrapolation using the acquired speed, location and majordirection of the object Ta assuming that it is a uniform motion, therebycalculating the movement locus, or the movement locus is calculated withan extrapolation assuming that it is a uniform motion. Alternatively,the movement locus is calculated with a known estimation method such asa least square method, a random sample consensus (RANSAC) method and aleast median square (LEMEDS) using the movement history of the objectTa. For example, as shown in FIG. 6 , the movement locus Tat of theobject Ta in the local coordinate of the vehicle 50.

The CPU 101 determines the posture of the object Ta, that is, determineswhether a deviation between the major direction Tad and the movementlocus is larger than a predetermined determination value (step S105).Specifically, the CPU 101 determines whether a angle θ formed betweenthe major direction Tad as a current direction of the object Ta and thetangential line Tt1 of the movement locus Tat is larger than apredetermined angle θr, that is, determines whether it is θ>θr. Thepredetermined determination angle θr may be from 30° to 40°, whendetermining more strictly, the angle θ may be from 20° to 30° and whendetermining with a relaxed condition, the angle θ may be from 40° to 50°

The CPU 101, when determined that the angle is θ>θr, that is, thedeviation between the posture of the object Ta and the movement locusTat is larger than the predetermined determination value (step S104:Yes), reduces the reliability (step S106). The CPU 101 executes thecollision determination process (step S110) to determine whether acollision risk is present between the object Ta and the vehicle 50 usingthe determined reliability, determine the driving assist level, transmitthe command signal to the driving assist control execution unit 30 andterminates the process. The CPU 101, when determined that the angle isnot θ>θr, that is, the deviation between the posture of the object Taand the movement locus Tat is smaller than the predetermineddetermination value (step S104: No), sets the reliability to be thereference reliability (step S108). The CPU 101 executes the collisiondetermination process (step S110) to determine whether a collision riskis present between the object Ta and the vehicle 50 using the determinedreliability, determine the driving assist level, transmit the commandsignal to the driving assist control execution unit 30, and terminatesthe process.

According to the collision determination apparatus 100 of theabove-described second embodiment, since the posture of the object Taand the movement characteristics of the object Ta, in particular, themovement locus Tat of the object are utilized to determine thereliability of the movement characteristics, the individual differencesof the detection elements and the environmental influence are suppressedor excluded, thereby improving the collision determination accuracy.Specifically, in the case where the angle θ formed between the currentmajor direction Tad of the target Ta and the tangent line Tt1 of themovement locus Tat at the current location is larger than thedetermination angle θr, the reliability of the movement locus isreduced. Also, in the case where the angle θ formed between the currentmajor direction Tad of the target Ta and the tangent line Tt1 at thecurrent location is smaller than or equal to the determination angle θr,it is determined that the movement locus Tat satisfies the reliability.As a result, even in a case where the individual differences of thedetection elements and the environmental influence influence thecollision determination apparatus 100, with the reliability as an index,it can be determined whether a collision risk is present based on thedetermination level depending on the reliability. Further, a level ofthe driving assist operation can be set depending on the reliabilitysuch that an erroneous determination and execution of unnecessarydriving assist process are reduced, thereby improving the collisiondetermination accuracy.

Third Embodiment

A collision determination apparatus according to the third embodimentdiffers from the collision determination apparatus 100 of the firstembodiment in which the velocity vector V of the object Ta is used andthe collision determination apparatus 100 of the second embodiment inwhich the movement locus Tat of the object Ta is used, in that a speedacquired using the detection results of a plurality of detection unitsis used for the movement characteristics of the object Ta whendetermining the reliability. Since other configurations of the presentembodiment are the same as those in the collision determinationapparatuses 100 according to the first and second embodiments, the samereference numbers are applied to the same configuration and the detailedexplanation will be omitted.

The collision determination apparatus according to the third embodimentincludes a collision determination program Pr1 stored in the memory 102.The collision determination program Pr1 functions to determine thereliability in accordance with the posture and the speed acquired usingthe detection result of a plurality of detection units. With referenceto FIG. 7 , an object detecting process executed by a collisiondetermination apparatus 100 according to the third embodiment will bedescribed. A processing routine shown in FIG. 7 is repeatedly executedat predetermined intervals, for example, every few milliseconds, afterthe control system of the vehicle 50 is activated or a start switch isturned ON. The CPU 101 executes the collision determination program Pr1,thereby executing the process flow shown in FIG. 7 . In the followingdescription, process steps S206, S208 and S210 which are similar tothose executed by the collision determination apparatus 100 according tothe first embodiment are applied with the same reference numbers asthose in the first embodiment and the detailed explanation will beomitted.

The CPU 101 acquires detection result of the object Tb, as an object tobe determined whether a collision risk is present, detected by thecamera 20 and the millimeter wave radar 21 via the input-outputinterface 103 (step S200). According to the present embodiment, apedestrian is regarded as an object Tb. The CPU 101 acquires a pluralityof movement characteristics of the object Tb (step S202) using theacquired detection result. The movement characteristics indicate featureof behavior of the object Tb over time. According to the presentembodiment, the movement characteristics is a speed of the object Tb.Specifically, a plurality of speeds acquired using detection result of aplurality of different types of detection units are acquired as themovement characteristics of the present embodiment. The different typesof detection units also refer to different types of detection methods ofthe object Tb, including an imaging method, a millimeter wave radarradiation method, an infrared light emission method, for example.According to the present embodiment, as shown in FIG. 8 , as a pluralityof movement characteristics, a camera speed Vi acquired using a capturedimage as a detection result of the camera 20 and a millimeter wave radarspeed Vm acquired using reflection point group as a detection result ofthe millimeter wave radar 21 are used. Further, a fusion speed Vf may beused in which a detection result of the camera 20 and a detection resultof the millimeter wave radar 21 are combined.

The CPU 101 determines whether speeds detected using a plurality ofdetection units, that is, a deviation between the camera speed Vi andthe millimeter wave radar speed Vm is large (S204). Specifically, theprocess determines whether a speed difference Vm between the cameraspeed Vi and the millimeter wave radar speed Vm is larger than apredetermined speed difference determination value Vdr. Thepredetermined speed difference determination value Vdr may be set, forexample, to be larger than or equal to 10 km/h, or may be set to be 5km/h for more strict determination or may be set to be 15 km/h for morerelaxed determination.

The CPU 101, when determined that the speed difference Vd correspondingto a plurality of detection units is larger than the predetermined speeddifference determination value Vdr, that is, Vd>Vdr (step S204: Yes),reduces the reliability (step S206). The CPU 101 executes the collisiondetermination process (S210) to determine whether a collision risk ispresent between the object Tb and the vehicle 50 using the determinedreliability and determine the driving assist level, transmits thecommand signal to the driving assist control execution unit 30 andterminates the present process routine. The CPU 101, when determinedthat the speed difference Vd corresponding to a plurality of detectionunits is smaller than or equal to the predetermined speed differencedetermination value Vdr, that is not, Vd>Vdr (step S204: No), sets thereliability to be the reference reliability (S208). The CPU 101 executesthe collision determination process (step S210) to determine whether acollision risk is present between the object Ta and the vehicle 50 usingthe determined reliability and determine the driving assist level,transmits the command signal to the driving assist control executionunit 30 and terminates the present processing routine.

According to the collision determination apparatus 100 of the thirdembodiment, since the movement characteristics of the object Tb,especially a plurality of speeds of the object Tb calculated using thedetection results acquired by a plurality of different types ofdetection units, the camera speed Vi and the millimeter wave radar speedVm are utilized to determine the reliability of the movementcharacteristics, the individual differences of the detection elementsand the environmental influence are suppressed or excluded, therebyimproving the collision determination accuracy. Specifically, in thecase where the speed difference between the camera speed Vi of theobject Tb and the millimeter wave radar speed Vm is larger than thepredetermined determination value Vdr, the reliability of the movementcharacteristics, that is, the camera speed Vi and the millimeter waveradar speed Vm is reduced, and in the case where the speed differencebetween the camera speed Vi of the object Tb and the millimeter waveradar speed Vm is smaller than or equal to the predetermineddetermination value Vdr, the process determines that the movementcharacteristics, that is, the camera speed Vi and the millimeter waveradar speed Vm satisfy the reference reliability. As a result, even in acase where the individual differences of the detection elements and theenvironmental influence influence the collision determination apparatus100, with the reliability as an index, it can be determined whether acollision risk is present based on the determination level depending onthe reliability. Further, a level of the driving assist operation can beset depending on the reliability such that an erroneous determinationand execution of unnecessary driving assist process are reduced, therebyimproving the collision determination accuracy.

Other Embodiments

(1) According to the above-described embodiments, the reliability isdetermined regardless of the types of the objects Ta and Tb. However,the reliability may not be determined depending on the types of theobjects Ta and Tb. For example, when the object Ta is a vehicle, a motorcycle or a bicycle, the above-described reliability is determined, andwhen the object is a specific object, for example, a pedestrian, thereliability may not be determined. Generally, it is difficult todetermine the major direction Tad for a pedestrian compared to that ofthe vehicle. Hence, an accuracy for determining a deviation between themajor direction Tad and a direction of the speed, or the tangent lineTt1 of the movement locus Tat may be lowered. In this respect, in thecase where the object Tb is a pedestrian, without determining thereliability, lowering of the collision determination accuracy can bereduced or the collision determination accuracy can be prevented frombeing lowered.

(2) According to the above-described embodiments, the camera 20, themillimeter wave radar 21 and the LIDAR 22 mounted on the vehicle 50 asdetection units are exemplified. However, detection units mounted onother vehicles as the object Ta may be utilized. In this case, thedetection results detected by the detection units mounted on othervehicles can be received via the inter-vehicle communication or theroad-vehicle communication, and the movement characteristics such as thespeed and the posture of other vehicle can be acquired using thereceived detection result. Also, individual differences and detectionerrors may occur in the detection units mounted on other vehicles, anddetection errors due to communication delay may occur. In contrast,according to the above-described embodiments, in the case where thereliability is determined, the individual differences and the detectionerrors can be reduced or eliminated.

(3) According to the above-described embodiments, the orientation may becorrected relative to the own vehicle using the output result of the yawrate sensor 25, whereby the positional relationship (posture) with theobject Ta. In this case, the detection accuracy of the speed of theobject Ta may be further improved.

(4) According to the above-described embodiments, the CPU 101 executesthe collision determination program Pr1, thereby achieving the collisiondetermination apparatus 100 in which the reliability of the movementcharacteristics is determined using the postures of the objects Ta andTb and the movement characteristics, or the reliability of the movementcharacteristics is determined using a plurality of speed differences asa plurality of movement characteristics of the objects Ta and Tbacquired using the detection results of a plurality of differentdetection units. However, the collision determination apparatus 100 maybe achieved by a hardware such as a pre-programmed integrated circuit ora discrete circuit. The control unit and method thereof in theabove-described embodiments may be accomplished by a dedicated computerconstituted of a processor and a memory programmed to execute one ormore functions embodied by computer programs. Alternatively, the controlunit and method thereof disclosed in the present disclosure may beaccomplished by a dedicated computer provided by a processor configuredof one or more dedicated hardware logic circuits. Further, the controlunit and method thereof disclosed in the present disclosure may beaccomplished by one or more dedicated computer where a processor and amemory programmed to execute one or more functions, and a processorconfigured of one or more hardware logic circuits are combined.Furthermore, the computer programs may be stored, as instruction codesexecuted by the computer, on a computer readable non-transitory tangiblerecording media.

The present disclosure is described in accordance with the embodimentsand modifications. The above-described embodiments of the invention isto readily understand the present disclosure and does not limit thepresent disclosure. The present disclosure may be appropriately changedand improved without departing from the sprit thereof or the scope ofclaims and may incudes equivalents thereof. For example, embodimentscorresponding to technical features of respective embodiments indicatedin the summary section and the technical features in the modificationexamples are appropriately replaced or combined in order to solve a partof or all of the above-described issues or to achieve a part of or allof the above-described effects and advantages. The technical featurescan be appropriately removed unless the technical features thereof aredescribed as necessary in the present specification.

(Conclusion)

As a first aspect, a collision determination apparatus is provided. Thecollision determination apparatus according to the first aspect isprovided with an acquiring unit that acquires movement characteristicsof an object to be determined whether a collision risk is present; and areliability determination unit that calculates a movement locus of theobject using the acquired movement characteristics and determines areliability of the calculated movement locus of the object.

According to the collision determination apparatus of the first aspect,influence of individual difference of the detection units and anenvironmental influence is capable of being suppressed or eliminated toimprove the accuracy of the collision determination.

As a second aspect, a collision determination apparatus is provided. Thecollision determination apparatus according to the second aspect isprovided with an acquiring unit that acquires movement characteristicsof an object to be determined whether a collision risk is present usinga detection result acquired from a plurality of types of detectionunits; and a reliability determination unit that determines areliability of the movement characteristics. The reliabilitydetermination unit determines the reliability to be low when adifference of speeds between objects corresponding to the plurality oftypes of detection units included in the movement characteristics islarger than a predetermined speed difference.

According to the collision determination apparatus of the second aspect,influence of individual difference of the detection units and anenvironmental influence is capable of being suppressed or eliminated toimprove the accuracy of the collision determination.

As a third aspect, a collision determination method is provided. Thecollision determination method according to the third aspect is providedwith steps of acquiring movement characteristics of an object to bedetermined whether a collision risk is present; calculating a movementlocus of the object using the acquired movement characteristics anddetermining a reliability of the calculated movement locus.

According to the collision determination method of the third aspect,influence of individual difference of the detection units and anenvironmental influence is capable of being suppressed or eliminated toimprove the accuracy of the collision determination.

As a fourth aspect, a collision determination method is provided. Thecollision determination method according to the fourth aspect isprovided with steps of acquiring movement characteristics of an objectto be determined whether a collision risk is present using a detectionresult acquired from a plurality of types of detection units; anddetermining a reliability of the movement characteristics to be low whena difference of speeds between objects corresponding to the plurality oftypes of detection units included in the movement characteristics islarger than a predetermined speed difference.

According to the collision determination method of the fourth aspect,influence of individual difference of the detection units and anenvironmental influence is capable of being suppressed or eliminated toimprove the accuracy of the collision determination. Note that thepresent disclosure can be achieved as a control program of a collisiondetermination program or a computer readable media that stores thecontrol program.

What is claimed is:
 1. A collision determination apparatus comprising:an acquiring unit that acquires a posture and movement characteristicsof an object to be determined whether a collision risk is present; and areliability determination unit that determines a reliability of themovement characteristics using the posture and the movementcharacteristics acquired by the acquiring unit.
 2. The collisiondetermination apparatus according to claim 1, wherein the movementcharacteristics include a speed of the object; and the reliabilitydetermination unit determines that the reliability is low when an angleformed between a direction of the speed at a current location of theobject and a current direction of the object determined using theposture is larger than a predetermined determination value.
 3. Thecollision determination apparatus according to claim 1, wherein themovement characteristics include a movement locus of the object; and thereliability determination unit determines that the reliability is lowwhen an angle formed between a direction of a tangential line of themovement locus at a current location of the object and a currentdirection of the object determined using the posture is larger than apredetermined determination value.
 4. A collision determinationapparatus comprising: an acquiring unit that acquires movementcharacteristics of an object to be determined whether a collision riskis present using a detection result acquired from a plurality of typesof detection units; and a reliability determination unit that determinesa reliability of the movement characteristics, wherein the reliabilitydetermination unit determines the reliability to be low when adifference of speeds between objects corresponding to the plurality oftypes of detection units included in the movement characteristics islarger than a predetermined speed difference.
 5. The collisiondetermination apparatus according to claim 1, wherein the reliabilitydetermination unit does not determine the reliability when the object isa specific object where a type of the object is a predetermined type. 6.The collision determination apparatus according to claim 1, wherein thecollision determination apparatus includes a determination unit thatdetermines whether a collision risk with the object is present; and thedetermination unit lowers a level of a collision avoidance assistprocess, executed by a collision avoidance assist execution unit, forthe vehicle.
 7. A collision avoidance system comprising: a collisiondetermination apparatus including: an acquiring unit that acquires aposture and movement characteristics of an object to be determinedwhether a collision risk is present; a reliability determination unitthat determines a reliability of the movement characteristics using theposture and the movement characteristics acquired by the acquiring unit;and a determination unit that determines whether a collision risk withthe object is present, wherein the determination unit lowers a level ofa collision avoidance assist process of a vehicle executed by acollision avoidance assist execution unit.
 8. A collision determiningmethod comprising steps of: acquiring a posture and movementcharacteristics of an object to be determined whether a collision riskis present; and determining a reliability of the movementcharacteristics using the acquired posture and the movementcharacteristics.
 9. A collision determining method comprising steps of:acquiring movement characteristics of an object to be determined whethera collision risk is present using a detection result acquired from aplurality of types of detection units; and determining a reliability ofthe movement characteristics to be low when a difference of speedsbetween objects corresponding to the plurality of types of detectionunits included in the movement characteristics is larger than apredetermined speed difference.